This is a good quality Silvolite standard piston and rings set for the 403 Olds, as found in 77-79 Firebirds & Trans Am. They are cast pistons.

Stock sizes are Std. 020 & .30. Sizes outside of this are normally ordered especially only>

Keep in mind too.. this is much better purchased in a kit where all the other parts come together also.. but if you need pistons & rings... we gott'm.